This invention relates to a service switching point equipped with a function for creating detailed charging information, as well as a system for creating detailed charging information. More particularly, the invention relates to a service switching point for creating detailed charging information composed of charging information for charges associated with additional services and charging information for charges associated with ordinary services, which are services other than the additional services, as well as a system for creating detailed charging information, in which the system has the above-mentioned service switching point and a service control point equipped with an additional-service control function.
An exchange having a function for collecting data for detailed charging (AMA data) is adapted to collect, as detailed charging data associated with a call, basic call data and information relating to an additional service if the additional service is used, wherein the basic call data includes a calling party number, a called party number, outgoing call time and call end time (or call duration), etc. It should be noted that "AMA" is the abbreviation of "automatic message accounting system". The AMA data is edited by software in the exchange whenever a single call ends and is stored in an external unit such as a magnetic tape. In a prior system for creating detailed charging information, the items of the charging information collected as the AMA data and the editing format thereof are incorporated in the software of each exchange. Accordingly, in a case where it is necessary, to, change or add to a collected item of information or to editing format owing, say, to introduction of a new service, the software of all exchanges that perform editing of AMA data must be updated individually.
In a network in which an intelligent network (IN) has been introduced, an architecture is adopted in which the exchange (the service switching point, or SSP) provides a predetermined switching operation and service control is performed by a service control point, or SCP.
FIG. 16 is a block diagram illustrating the configuration of a communication network in which an intelligent network has been introduced. The network includes a service switching point 1 having a switching function, a service control point 2 having an additional-service control function, a No. 7 signaling network 3 that performs an exchange of signals between the points 1 and 2, and a number of telephone terminals 4, 5, . . . . The service switching point 1 is equipped with a number of exchanges 1a, 1b, . . . , each of which has a network switching module NW and a central processing unit CCP. Also included, although not shown, are a subscriber circuit, a relay trunk circuit and an external unit such as a magnetic tape. The service control point 2, which is constituted by a computer, is capable of exchanging data with each exchange and is equipped with a processor CPU, a memory MM for storing a service program, and a data base DB for storing data needed to execute the additional service (IN service). When a call accompanied by a special number is placed from an originating subscriber A in such an intelligent network, the exchange 1a on the originating side gives notice of this special number to the processor CPU of the service control point 2, and the processor CPU executes service analysis of the entered special number in accordance with the service program SVP. If a service such as a free dialing service or transfer service is requested by the special number, the processor obtains the telephone number of a terminating subscriber B from the data base DB, notifies the originating exchange 1a of the results of analysis (the telephone number, etc.) and establishes an ordinary path by means of the service switching point 1.
FIG. 17 is a diagram showing the operating sequence in service control of a free dialing call (billing of the terminating side). 1 When a subscriber transmits an access code ***** (where * is a numerical value), 2 the SSP, which is the exchange, verifies free dialing and makes an inquiry of the SCP regarding the destination of the connection. 3 The SSP subsequently creates free-dialing charging information. 4 The SCP, on the other hand, goes to the data base DB to obtain the telephone number of the connection designation corresponding to the access code ***** and instructs the SSP of this telephone number. 5 As a result, a connection is made with the party and 6 a call is established. 7 When an on-hook (disconnect) operation is carried out in response to the end of a call, 8 the SSP creates AMA data that contains free-dialing charging information.
FIG. 18 is a diagram showing the composition of the record of AMA data having a variable-length structure. Numeral 6a denotes a record descriptor word in which the byte length of the AMA data is entered, 6b the record type in which the fact that the record is the AMA data record is entered, 6c a basic part in which is entered such basic call information as the calling party number, the called party number, outgoing call time and call end time, as well as additional-service information, etc., 6d an extended part in which extended information (information identifier, information field length and information content) is entered, and 6e a stopper (all "0" s) indicating end of the AMA data. The basic part 6c has the items shown in FIG. 19. Specifically, the following items are entered in the basic part 6c: byte length 6c-1 of the basic part, AMA record serial number 6c-2, data record type (distinguishes between ISDN residential call and analog residential call) 6c-3, charged party identifier (distinguishes among calling party, called party and third party) 6c-4, distinction 6c-5 between basic call and additional-service call, charging method 6c-6, calling party information (calling party number, etc.) 6c-7, called party information (called party number) 6c-8, call established date and time 6c-9, call answer time 6c-10, call release time 6c-11, duration of call 6c-12, . . . , additional service identification indicator 6c-21 and charged party number 6c-22.
Accordingly, in control 3 of the free-dialing call service, charging information (items 6c-5, 6c-21, 6c-22) of the additional service is created and the remaining items of the basic part are created at 8 to produce the AMA data.
When a new service is introduced in a communication network to which an intelligent network has been introduced, this is dealt with only by interchanging the files (changing the software) of the service control point SCP unless there is a change in the switching operating of the service switching point SSP, and it is unnecessary to interchange the files (the software) of the SSP.
In the prior art, however, all of the charging information inclusive of that for an additional service is created by the software of the SSP. Consequently, when it is necessary to make a change or addition to an item of collected information or to an editing format when a new service is introduced, it becomes necessary to change the SSP software for the creation of detailed charging information even if there is no change in the switching operation. In other words, a problem with the prior art is that the software of the SSP must always be changed when a new service is introduced.